Sparking plug.



l fk %db F. W. ERICKSON.

SPARKING PLUG.

APPLICATION FILED JAN. 19, 1912.

1,044,509. Patented Nov. 19, 19121 JIM 222E017 gawk. Mam

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- To all whom it may concern: I

UNITED s'rAtrEs PATENT CFFICE'I' rnnimmo wm. nmoxson, or YORK, N. it.

sraaxmo' ,PLUG? Application?! January 19, 1812. Serial lie. 872,147.

Be it knownthat I, Fnnnmno WM. Enronson, residing at New York, in thecounty of New York and State of New York, have invented certainImprovemehts in Sparking Plugs, of which the following is a.specification.

' The present invention relates to improvements in-sparkin plugs orelectric igniters for internal com ustion motors, and rovides meanswhereby the liability of fou ing and short circuiting will be reduced toa minimum, and means for intensifying and I i increasing the caloricvalue of the produced spark and means whereby the spark gap may bemaintained at a determined or calibrated space as in multiple cylindermotors; in order to produce the best results, the length of the sparkgap in each cylinder should be accurate to WlfihlIl a small fraction ofan inch. All of which I will now proceed to describe and point out inthe claim, reference being had to the accompanying drawings whichillustrate the specification and form a part thereof, of which Figure 1is an elevation. in one-half section of a spark plug embodying myinvention. Fig. 2'is a view of'the lower end of the former figure, andFig. 3 ,is a side view of an insulating washer or disk.

In the drawings A; is a metal shell, whose upper end 2 is provided withan internal screw-thread 2 and with a ledge C upon which rests aninsulating disk or washer i, preferably of mica of a calibrated ordetermined thickness, the lower ortion being of reduced diameter whoseun er part 2 forms a bearing to rest upon the frame of the motor, wherethe threaded shank 2 is screwed into the proper opening to the explosionchamber of the motor.

C is a metal collar having an external screw-thread to engage with thethread 2 of the shell A, and has an internal shoulder h adapted to holdthe insulating post (I firmly to the upper part of thewasher z. Theupper end of the insulating post d is fitted with a metal cap 0 whichserves as a protection of the material composing the same and its lowerend is tapered and enlarged and fits snugly within the tapered up er endof the collar C.

' is a metal rodwhich passes through the insulating post d andterminates at its top in a screw-threadupon which is a nut a above whlchs the nut 7 adapted to engage a terminal wlrew; at the lower end of thewhenv the nut e is turned down hard retains the sections A, O and (Itogether. From the "enlargement 1 the rod Z tapers down to a bulb 1"which serves as an electric discharge terminal, the opposite terminalbeing formed from the rounded finial of the shell A, which has thecross-cut perforations or openings m, m, in 'its end forming the sharpcorners 2 which are bent inwardconstitutin spark points Within theinterior of the she I. The

enable itto be passed over the end 1 of the rod Z to near the enlarement 1 and profrom heat due to the sparking, and is made of a.calibrated or determined thickness so that the gap between terminal 1and the points 2 will be the same, whenever, if the outer surfacebecomes coated with soot it becomes desirable to substitute a new one,and as the expense is slight any number of them may be, kept on hand andan old one quickly replaced by a new.

The circularchannel 9 in the lower end of the insulating post d isconcentric and serves to increase the insulating area in case the washeri should by accident get punctured. By the. use of the removableinsulating washer i the chamber j of the shell A is kept comparativelyclean and free from soot which collects mainly in its upper end, as itisso easily replaced when foul by a new one, and serves to lengthen thelife of the plug which often has to be replaced by a new plug after anautomobile run of 1,000 miles, and as the washers are carefully made ofthe same thickness the accuracy of the calibration of the spark ismaintained.

Having described the invention, I claim;

A sparkplug composed of a metal shell having'a rounded perforated lowerend with inwardly bent sparking points, a supporting ledge in the upperpart of the shell, a perforated mica disk resting on the ledge, aperforated insulating post whose lower end extends into the upper partof the shell, a collar adapted to bear upon the exterior of the post andupon the edge of the disk and hold the same tothe shell, with a metalrod extending through the interior of the shell post 1 the rod lhas anenlargement 1 which teots the lower end of t e insulating post (3Patented Nov. 19, 1912.

mica disk'or washer i has a central hole to Y and the post one end ofwhich is seperated two subscribing witnesses, from the sparking polntsa; a 3111p, while January, 1912. the ogposite end is provid W1. a screwthrea and a nut at the upper end of the 5 post, as set forth. Witnesses:In testimony whereof, I have signed my -HARRIIT LEVI, name to thisspecification in the presence of JOHN A. Cow.

FREDERIO W this 16th 'day of ERICKSON.

